Slider for separable fasteners



Jan. 3, G PRENTICE L89337 SLIDER FOR SEPARABLE FASTENERS Original Filed June 29, 1928 atented Jan, 3,, i133 l tditdtf GEORGE E. PRENTICE, F BERLIN, CONNECTICUT sLrnEn non sErAnAnLn nesrnnnns Original application filed June 29, 1928, Serial No. 289,288. Divided and this application filed. March 12,

1931. Serial This invention pertains to separable fasteners of that type of which a good example is disclosed in the patent to Prentice and Legat, No. 1,658,392 dated February 7, 1928,

r and relates more particularly to an improved slider for use in fasteners of this general kind, the method or process of making the same being the subject of my copending application Serial No. 289,288, filed June 29, 1928, of

which the present is a divisional application.

The usual form of slider employed in such fasteners comprises spaced substantially parallel front and rear wings or plates united at or near one end by a relatively narrow connecting portion or neck, the inner opposed surfaces of the wings having cam-like members which, in cooperation with certain ele ments associated with the connecting member or neck, define guides for the opposed series 0 of fastener elements. The successful operation of such a slider is dependent upon the maintenance of the wings in accurately spaced relationship,'but as the wings are united at or near one end only and as the slider is subjected to severe stresses tending to spread the wings apart, diiiiculty has been experienced in making a slider sufiiciently rigid without making it unduly heavy and cumbersome.

Various modes of making such sliders have heretofore been proposed. For example, at-

tempts have been made to produce them by drop forging or die casting, but such meth-e ods are expensive and from the nature of the operation, the resultant sliders are heavy,

cumbersome, rough, and generally unsatisfactory. A more common and fairly successful method consistsin making the slider of sheet metal by punching; and bending operations, but since sheet metal bends so easily, it is usuo ally necessary to reinforce a sheet metal slider by means of rivets, external yoke pieces, ribs or the like, requiring several successive operations in the manufacture of such a slider, thereby increasing the cost of production, while the finished slider often presents a clumsy, angular, and unple'asing appearance. Tn one proposed modification of the sheet metal slider, the metal at theneck of the'blank is swaged to provide a heavy projecting rib, and when the blank is bent this rib, which is disposed at the inner side of the bend, provides extra thickness designed to give greater stifiiness at this point. However, in bending the blank, this heavy rib merely folds upon itself, leaving a crack or fissure between its contacting faces, and as the fibers of the thick metal are heavily stressed and distorted in bending, this arrangement in reality afiords little, if any, more resistance to separation of the wings than does the ordinary unreinforced sheet metal slider. -lfloreover, in such construction, even more than in other usual types of slider, the inner surface of the neck is irregular, rough and varies in configuration in difierent sliders, and as this inner surface of the neck acts like a cam in performing the important function of guiding the opposed series of fastener elements as they approach and recede, the slider so constructed often fails to work with the desired ease and smooth i ness.

In accordance with the present invention I provide a slider possessing the inherent stiffness and strength which results from intcgral homogeneous construction and which works with the greatest ease and smoothness, but which is markedly different from other integral constructions produced by die casting or the like operations in that it is light in weight, of small dimensions and of pleasing appearance. The new slider also represents a distinct advance over usual sheet metal constructions in its neatness, freedom from external. stiffener yokes or ribs, low cost of production and small size. This slider may be used with fasteners of the kind in which each series of fastener elements consists of independent members attached to a flexible stringer, as illustrated for example in my aforesaid patent,or of the general type described in my Patent No. 1.562.253, November 17, 1925, in'which the fastener elements of each series form portions of a continuous lengthof wire. I

I produce the slider from a solid metal blank of proper dimensions preferably by a mechanical process or method in which the principal parts of the slider body result solely from cutting so that the normal fibrous structure of the metal is not disturbed or unduly stressed, and although certain minor features require bending or similar operations, no substantial weakening of the slider body results therefrom. All of the various steps in the production of the slider body are readily performed by proper mechanisms at high speed and with low labor cost, resulting in a product of accurately uniform and finished character capable of performing its intended function with the highest ease and efiiciency, and exhibiting surprising strength and rigidity as compared with sliders formed by swedging and bending sheet material.

In the accompanying drawing, I have illustrated one desirable embodiment ofthe present invention, and have shown certain desirable steps in a preferred method of producing the improved slider, but wish it, to be understood that the specific construction here illustrated and the several steps and the order of steps here disclosed are by way of example only and are not to be regarded as limiting the scope of the invention.

In the drawing:

Fig. 1 is a fragmentary front elevation, to large scale, showing a fastener of the general type above referred to, provided with a slider constructed in accordance with the present invention;

Fig. 2 is a composite view showing in front elevation and in edge elevation, respectively, a blank of a desirable shape for use in constructing the improved slider;

Fig. 3 is a composite view showing in front elevation and in edge elevation, respectively, the appearance of the blank after it has been subjected to a suitable operation for producing a projection on its forward face adapted, at a later stage, to constitute a retainer for a pull device;

Fig. 4 is an edge elevation of the blank at the end of the cutting operation which results in the formation of the front and rear wings of the slider;

Fig. 5 is a vertical section on the line 55 of Fig. 4;

Fig. 6 is a. front elevation of a pull device of a type which may conveniently be assembled with the slider body herein disclosed;

Fig. 7 is an edge elevation of the complete slider, showing the inturned guide flanges at the edges of the front and rear wings and the line means? Fig. 13 is a,vie'w similar to Fig. 12 but edges the series 3 and 4 respectively of fastener elements are secured. As here shown, thesefastener elements are of the type more fully disclosed in the patent to Prentice and Legat No. 1,658,392 above referred to, but while this particular form of fastener is here illustrated, it is to be understood that the improved slider forming the immediate subject matter of the present application is applicable to other types of fastener as well as to that here specifically shown.

' In the production of the improved slider, I first prepare a blank 6 from the material to be employed, (usually, although not necessarily metal) having roughly the outline and dimensions of the finished slider body. This blank may be cut, punched, or otherwise formed from sheet material. As indicated in Fig. 2, the blank is of more or less key stone contour, comprising the top face 7, the

bottom face 8, the lower lateral edge surternal size and contour of the finished slider body. At the same time, I prefer to form an integral projection on one face of the slider, preferably the front face, which later forms an anchorage for the pull device as hereafter described. In Fig. 3 I have-shown the result of this shaping operation, it being noted that the lower face 8 of the blank has become longer than in Fig. 2 and that the edge faces 9 and 10 have taken an arcuate concavecurvature. In Fig. 3 the projection 13 formed in this operation is shown as extending from the top 7 to the bottom 8 of the slider body. While it is desirable to proceed as above described since the compression of the metal in thus shaping vit adds to its density and homogeneity, I contemplate that if desired the original blank may be made of the proper thickness, lateral dimensions and contour to correspond to the finished slider body and that other means than the projection 13 might then be employed for attaching the pull device. 1

In whatever manner the final blank of Fig. 3 be formed, it is now subjected to a cutting operationwhereby material from the interior of the blank is removed, leaving a slot 14 intermediate'the front and rear portions 15 and 16 which now constitute the front and rear reeaoar wings of the slider. Preferably this slot 14 is produced by a milling operation which leaves the front and rear faces of the blank intact and which makes the opposed inner post or block 17, which will hereinafter be.

referred to as the neck of the slider, in accordance with terminology usually employed in this art, is of substantially triangular shape. As shown in Fig. 5, the upper face 7? of this neck preferably coincides. with the upper surface 7 of the blank, while the converging sides 18 and 19 of this neck member meet at a point "20 substantially below the surface 7* and preferably about midway between the top and bottom surfaces 7 and 8 of the slider body. Preferably, the edge faces '18 and 19 of this neck member are concavely curved upon arcs more or less concentric with the curved edges 9 and 10 of the body. If the slot 14 be produced by a milling operation, these curved-surfaces l8 and 19 may well conform to the curvature of the edge of the milling cutter and as here illustratechloy way of example, these surfaces are such as would be produced by a milling cutter having straight cutting edges. Surfaces generated by the movement of a straight line are known as ruled surfaces, and if the straight line follows a plane directing curve (of whatever contour) the resulting surface, while generically aruled surface is more specifically a cylindrical surface. In the present instance the surfaces 18 and 19 are curved only in planes parallel to the slider wings and all elements of these surfaces which are perpen-' dicular to the wings are substantially rectilinear. These surfaces are smooth, uninterrupted, and without abrupt changes in shape, and are eminently well adapted to pertill form the function ofguides for the opposed series of fastener elements.

In thus forming the slot 14 by a cutting operation, the metal of the slider body is not distorted or subjected to injurious stress, and the fiber of the metal in the neck portion 17 remains undisturbedand retains all of its original strength and ability to resist deformation. Referring to Fig. 11, it may be noted that the post or neck 17 is of homogeneous composition, wholly without folds, seams, sutures or the like, and thus throughout its entire depth possesses the inherent and original strength of the metal of the blank. This neck member 17, extending as it does downwardly from the upper surface of the slider body to a point substantially midway the resistance to separation of the front and rear 'wings, so that no external yoke or strengthening rib extending around the neck portion of the slider is necessary. The external dimensions of the slider body are thus kept at a minimum: The rear wing 16 at least of the slider body is wholly free from any projection, while the neck portion is also free of any projecting rib and is preferably flush with the upper surface of the 'slider body.

The nextstep in the operation preferably consistsin bending the lateral edge portions of one or both of the wings inwardly to form guide flanges E23 and 2e. While I have here shown both the front and rear wings as provided with such guide flanges, I contemplate that when the slider is to be used with certain types of fastener element, it will not be necessary to provide lateral guide flanges upon one of the wings.

Referring to Fig. 8, it may be noted that the depth of the neck 17 is such that it extends 'ment of the opposed fastener elements is as.

sured.

At some convenient point in the operation, either before or after the formation of the lateral flanges 23 and 24,1 subject the projection 13 to a suitable operation or operations to adapt it for the reception of a pull device. As shown in Fig. ,7 the projection has been pierced transversely to provide the elongate slot 28, leaving on y the outer portion of the projection to form an elongate loop 13 integrally united at its upper and lower ends to the front wing of the slider body. To this loop I attach a suitable pull device which may, for example, be of the type shown in Fig. 6. This pull device comprises a piece of sheet material 29 cut to proper shape and having an opening 30 into which leads a slit 31 defining spaced pivot ears 3:? and 83. In assembling the pull with the slider body the cars 82 and 33 may be sprung or bent apart sulliciently to enable them to be entered into the slot 28. whereupon they are returned to their original position, thus forming pivoting elements for securing the pull to' the loop 13'. In order to impart a pleasing appearance, the exposed surfaces of the slider may, if desired, be polished, plated, enameled, or otherwise finished appropriately to the use to which it is to be put.

The slider thus completed may be assembled with any desired form of fastener of the general type referred to and by reason of the accuracy of finish of its interior surface is found to operate much more smoothly and easily than any previously known form of slider. At the same tilne, this improved slicler is extremely rigid; it is very small; of minimum front to rear thickness; and of neat and pleasing appearance.

While the arrangement shown in Fig. 7 is desirable in providing an elongate loop 13, which permits the pull to be positioned either at the top or bottom of the slider,l contemplate that, as shown in Fig. 12, the loop 13 may be of smaller dimensions, being located preferably at the central part of the front wing 15 of the slider and having a relative ly small opening 28* for the reception of the pivot elements of the pull.

In Figs-13 and 14 I have shown a further modification in the production of which the original projection on the front face of the wing is of the same length, as shown in Fig.

3, but wherein the projection is not perforated through its entire thickness,'as shown in Fig. 7, but merely recessed at its opposite sides as shown at 28 providing socket slots for the pivot elements of the pull device, the outer member 13 of the projection remaining of its original transverse thickness.

While I prefer to provide integral means for attaching the pull device, as above described, I contemplate that the pull device may be secured by soldering or brazing directly or indirectly to the body of the slider at any desired point or may be attached in any other manner familiar to those skilled in the art.

While I have herein illustrated and described a certain desired order of steps useful in producing my improved slider, I wish it to be understood that this order of steps is not wholly essential but that the order may be varied and that it is within the scope of the invention to introduce other steps or, as above suggested, to omit certain of the steps here disclosed without departing from the spirit of the invention. Neither is it essential that the external contour of the slider body or of the blank from which it is made be inexact accordance with the present disclosure, or that )the original blank be produced by cutting or punching from solid stock although this method is preferred. \Vhile metal is preferred in most instances as the material from which this slider is made, I contemplate that other materials may be found useful for the purpose, and I regard the present method as applicable to the mak ing, of sliders from such other materials and 1 wish it to be understood that the claims appended hereto are not to be restricted by reference to the material employed.

I 'claim:

1. A slider for fasteners of the class deeases? scribed, said slider comprising a body consisting of a unitary piece of sheet metal having the desired external contour and having a substantially homogeneous internal fibrous structure, said piece of metal having milled grooves in its opposite sides to provide accurately dimensioned channels of substanially rectangular cross section converging at one end of said body and diverging adjacent to the opposite. end, the channels opening outwardly through said opposite sides and defining spaced front and rear wings, and a neck integrally united to said wings adj acent to one end of said body, said neck and wings retaining substantially unaltered the original fibrous structure of the piece of,

metal.

2. A slider for fasteners of the class described, said slider comprising a body consist ng of a unitary piece of sheet metal hav ing the desired external contour and havin g a substantially homogeneous fibrous structure, said body having milled grooves in its opposite sides to provide channels of substantially rectangular cross-sect on converging at one end of said body and diverging adjacent to the opposite end, the channels opening outwardly through said opposite sides and defin ng spaced front and rear wings, and a neck integrally united to said wings adjacent to one end of said body, said neck extending inwardly to the point of d vergence of said channels andhaving smooth lateral edges, said neck and wings retaining substantially unaltered theorigfnal fibrous structure of the piece of metal.

- 3. A slider for fasteners of the class described, said slider comprising a body consisting of a un tary piece of sheet metal having the desired external contour and having a substantially homogeneous internal fibrous structure, said body having milled channels on opposite s des converging at one end of said body and diverging adjacent to theopposite end, the channels opening outwardly through said opposite sides and defining spaced front and rear wings. and a neck integrally united to said Wings, said neck being substantially triangularin vertical section and having its inner apex disposed sub sta'ntially midway of the length of said slider body, the inner surfaces of the wings being smooth and accurately fiat and the lateral faces of the neck being cylindrically curved, sa d neck and wings retaining substantially unaltered the original fibrous structure of the piece of metal. i

4. A slider for fasteners of the class de scribed comprising a body consisting of a unitary piece of sheet metal having a substantially homogeneous internal fibrous structure, said body being of substantially. keystone shape and having milled channels of polygonal cross-section at its oppos te sides. said channels converging at one end of said aeaoer body and diverging adjacent to the opposite end, the channels opening outwardly through said opposite sides and defining spaced front and rear wings having marginal guide flanges, and a neck integrally uniting said wings, the outer surface of the neck being smooth and ribless, said neck being seamless throughout substantially its entire depth and constituting the sole means to prevent separation of the wings, the inner surfaces of the wings being accurately flat and the lateral faces of the neck being cylindrically curved, said neck and wings retaining substantially unaltered the original fibrous structure of the piece of metal.

5. A blank for use in forming a slider for separable fasteners of the class described, said blank comprising a piece of fibrous metal having a substantially keystone contour including a top face, a bottom face, upwardly divergent lower lateral surfaces and down- Wardly divergent upper edge surfaces.

6. A. blank for use in forming a slider for separable fasteners of the class described, said blank comprising a piece of fibrous sheet metal having plane front and rear faces and having a substantially keystone contour including a top face, a substantially parallel bottom face, upwardly divergent lower lateral surfaces, and downwardly divergent upper edge surfaces.

Signed by me at Berlin, Connecticut, this tenth day of March 1931.

GEORGE E. PRENTICE. 

